TDM-based Medium Access for Transporting Constant-Bitrate Traffic in Wireless LAN

• Main Authors: Yen-Tung Yeh, 葉燕東
• Other Authors: Guan-Hsiung Liaw
• Format: Others
• Language: zh-TW
• Published: 2011
• Online Access: http://ndltd.ncl.edu.tw/handle/32975220401231984143

碩士 === 義守大學 === 資訊工程學系碩士班 === 99 === Since the medium access mechanism, i.e. DCF (Distributed Coordination Function) of IEEE 802.11 WLAN adopts distributed contention with random backoff method, it will cause indefinite delay and jitter. Thus, it is not suitable for transporting the data which requires periodical transmissions, such as constant-bit-rate (CBR) VoIP speech flows. In this thesis, a novel TDMA-based medium access mechanism is proposed for IEEE 802.11-like WLANs to satisfy the QoS requirements of the CBR data flows. The proposed mechanism is developed by improving the original DCF scheme such that the stations can access the wireless medium in TDMA manner without any contention. With the proposed mechanism, the bandwidth of wireless medium can be efficiently utilized and larger delay jitter caused by contention can be avoided. In addition, the WLAN with the proposed mechanism can also co-exist with the original IEEE 802.11 WLAN.